Dyeing fibers, threads, or fabrics



inure arts 'TQHN FREDERICK BRIGGS AND CHARLES WILFRED PALMER, F SPONDUH, N

DERBY, ENGLAND, ASSIGNORS T0 AMERICAN CELL'UEOSE AND CHEMIC MANUFACTURING COMPANY LIMITED, A CORPORA'IIQN 0F DELAWE.

DYEING FIBERS, THREADS, 0R FABRICS.

) Ito Drawing.

To all whom it may concern:

Be it known that we, JOHN FREDERICK Braces and CHARLEsWILrnEn PALMER, subjects of the King of Great Britain, of Spondon, near Derby, England, have invented certain new and useful Improvements Belating to Dyeing Fibers, Threads, or Fabrics, of which the following is a specification.

This invention relates more particularly to the dyeing in any way of fibers, threads, or fabrics of or containing cellulose acetate.

It is known that cellulose acetates do not very readily absorb dyestuffs, and various proposals have been made for increasing their absorptive power.

It has now been found that the dyeing of fibers, threads, or fabrics of or containing cellulose acetate can be facilitated by means of ammonium thiocyanate, the absorptive power of the cellulose acetates for basic, acid, substantive, vat or other dyestuds being increased by the action of the thiocyanate on the cellulose acetate.

In carrying out the invention the thiocyanate treatment may be applied to the fibers, threads, fabrics or goods in any suitable or convenient way. Preferably it is applied thereto before the dyeing operation, but it may be applied in the dyeing operation, and the claims of this case to be so construed.

By way of example, the fibers, threads, fabrics or goods may be first immersed in an aqueous or other solution of the thiocyanate and then, after preferably washlng out the thiocyanate, be dyed with the dyestuffs in any known or suitable way. Or,

in the case of dyestuffs soluble to the re quired-extent in the thiocyanate solutions or in baths containing the same, the dyestutf may be dissolved in an aqueous, or other solution of the ammonium thiocyanate, or the thiocyanate be added to or incorporated in the dye bath or the like. From an economical point of view, however, it is best to treat the material first with a bath or solution of the thiocyanate and afterward'subject it to the dyeing operations.

The ammonium thiocyanate may be employed in an suitable quantity or strength of solution or the purposes of the inven- Specification of Letters latent.

ably according used, the strength of the thiocyanate solu- Patented Nov, 29 1921.

Application filed September 21, 1920. Serial No. 411,805.

tron, according to the particular dyes used, depth of shade required,'or other circumstances. Solutions' of about 1 to 25% strength, and preferably about to 25% strength may for example be employed, but we in no way restrict ourselves in this respect.

The length of time during which the cellulose acetate material is exposed to the act1on of the thiocyanate may vary considerto the particular dyestuffs t-ion,' t he depth of shade required or other condltlons; for example it may vary from 2 minutes to half an hour or an hour or more. The following; examples illustrate how the invention may be carried out.

Earamplc 1. Pretreatment of cellulose acetate silk with thiocg auazfe, and dyeingfrom an aqueous olg e bath.

(a) Example of basic (lyestuf.-Cellulose acetate silk is pretreated for about 3; hour at about 20 C. with a to aqueous solution of ammonium thiocyanate, washed free from thiocyanate in cold water, and then dyed for about hour at about C. in a dye bath containing 0.5 gram of methyl violet per 100 cc. of water.

(a) Emamplo of acia wool clyestu;7.-Cellulose acetate silk is soaked for about 20 minutes in a bath containing 15 to 20 grams ammonium thiocyanate per 100 cc. water, washed in cold water and dyed for about 15 minutes at about 20 C. in a bath containing 1 gram of coomassie acid blue R (Levinstein) per 100 cc. water.

(0) Example of direct cotton dycstu7?.- Cellulose acetate silk is pretreated for about {5 hour with a aqueous solution of am monium thiocyanate, washed in cold water and dyed for about 5; hour at about 20 C. in a dye bath containing 0.5 gram dianol fast red K (Levinstein) per 100 cc. water.

Ewamplc 2.- Dye bath containing tlw'ooy- (mate.

.dilute to 120 liters and filter.

100 liters with hot water. Good agitation or circulation of the bath is maintained during the dyeing.

Ervample 3. Example of the process as applied to eat dies.

' (a) Single bath process-500 grams purindone red B20% paste (Levinstein), 250 grams hydrosulfite of soda, 550 grams caustic soda, dissolved in water, heated at 50 C. until the dyestufi' is reduced, and then diluted to 50 liters. To this solution is added 50 liters of a 3 per cent. solution of ammonium thiocyanate. The silk is worked in the dye-bath at about 20 C., then exposed to the air, rinsed and acidified.

(6) Dyeing with etrcatment.--The silk is treated at the or inary temperature in a bath containing 125 grams of ammonium thiocyanate per liter for a period of one hour, or longer if desired. It is then dyed at 20 C. in a dye vat prepared in the manner prescribed for W001 dyeing. For instance 3.5 kilos burindone red B 20% paste (Levinstein), 2.5 kilos hydrosulfite of soda, 600 grams magnesia as magnesium hydroxid solution or calcium oxid as milk of lime; reduce by warming with water at 50 1., The bath should be kept slightly alkaline by small additions of magnesium hydroxid solution or lime water when necessary. After dyeing, the silk is exposed to the air, rinsed and acidified in the usual manner.

It is to be understood that the foregoing are only given by way of example and that the temperatures, concentrations, and other working details may be varied and any other suitable dyestuffs be employed within the spirit of the invention. For instance common adjuncts used in dyeing, such as salt for substantive dyes or a small percentage of acetic acid for acid and basic dyes, may be used if desired.

It is further to be understood that the invention can be applied to the dyeingof fabrics, fibers or threads, of cellulose acetate mixed with other textile fibers or threads Sliill for example as cotton, Wool or natural s1 The dyeing of such mixed fibers, threads or fabrics may be effected in any suitable way, for example it may be carried out on the lines of a cross-dyeing, i. e. dyeing successively with different dyes suit-able for the different fibers. By way of example one may first dye a piece of fabric consisting of cotton and cellulose acetate silk with such a direct cotton dye which the acetate silk does not take, or does not take to. the same extent as the cotton, and subsequently treat the fabric with the thiocyanate and, after washing out the thiocyanate, treat the fabric with a dye which the acetate silk will then take; or conversely, though less preferably one may first treat with the thiocyanate and dye with the acetate silk dye and afterward dye with the cotton dye. Analogous cross-dyeing treatment may be employed in the case of mixed fibers, threads or fabrics of cellulose acetate and wool, natural silk or other fabric. Or for the dyeing or coloring of mixedfibers threads or fabrics of cellulose acetate and cotton, wool, natural silk or other fibers, such dyes may be used as will dye both the cellulose acetate (With the assistance of the thiocyanate treatment) and the other fiber at the same time, the thiocyanate treatment being applied before or during the dyeing or coloring operation.

Instead of ammonium thiocyanate other thiocyanates may be employed for the purpose of the invention, such for example as sodium, potassium or calcium thiocyanates.

What we claim and desire to secure by Letters Patent is 1. The herein described method of facilitating the dyeing of fibers, threads or fabrics of or containing cellulose acetate, which comprises subjecting the same to the action of a thiocyanate in solution.

2. The herein described method of facilitating the dyeing of.fibers, threads or fabrics of or containing cellulose acetate, which comprises subjecting the same to the action of ammonium thiocyanate in solution.

3. The herein described method of facilitating the dyeing of fibers, threads or fabrics of or containing cellulose acetate, which comprises subjecting the same before dyeing to the action of a thiocyanate in solution.

4. The herein described method of facilitating the dyeing of fibers, threads or fabrics of or containing cellulose acetate, which comprises subjecting the same before dyeing to the action of ammonium thiocyanate in solution.

5. The improved method relating to the dyeing of fibers, threads or fabrics of or containing cellulose acetate, which comprises subjecting the same to the action of a thioc anate in solution, and afterward dyeing t e same.

6. The improved method relating to the dyeingof fibers, threads or fabrics of or containing cellulose acetate, which comprises subjecting the same to the action of ammonium thiocyanate in solution, washin out the thiocyanate from the material and afterward dyeing the same.

In testimony whereof we have hereunto subscribed our names.

JOHN FREDERICK BRIGGS. CHARLES WILFR-ED PALMER, 

